CNN: Sources say Sen. Larry Craig (R-ID) may resign as early as today.

Actually this is pretty remarkable if true:

A GOP source with knowledge of the situation told CNN's Dana Bash that the Republican National Committee was poised to take the extraordinary step of calling on Craig to resign.

However, that move was put on hold, the source said, because top party leaders have received indications that Craig himself is preparing to step down.

Sources have confirmed that high-level meetings on the matter were being conducted in Idaho on Thursday.

I don't recall a national party publicly calling for the resignation of a sitting senator of its own party ever before. Perhaps our Senate history buffs can help us here. More at TPM's Election Central.